<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>

    <script src="./jquery-3.6.0.min.js"></script>
</head>
<body>
<!--https://www.cnblogs.com/dw3306/p/9381720.html-->

1111<input  id="btn"  type="text"  onkeyup="fn(event)"  />

<script>
    function fn(e){
        alert(e.which)
        alert(11);
    }


    $("#btn").keydown(function(event){
     　　　if(event.keyCode == 13){
         　　　　alert('你按下了Enter');
      　}
          });
</script>
</body>
</html>